MATERIALS AND METHODS: An in vitro monocyte recruitment model utilizing THP-1 and HUVECs was developed to evaluate TNF-α-induced monocyte adhesion and trans-endothelial migration. To study the role of Nrf2 for MA-mediated anti-inflammatory effects, Nrf2 inhibitor ML385 was used as the pharmacological inhibitor. The expression of Nrf2, monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1), cluster of differentiation 36 (CD36), and scavenger receptor type A (SR-A) in HUVECs and THP-1 macrophages were investigated using RT-qPCR and Western blotting. The NF-κB activity was determined using NF-κB (p65) Transcription Factor Assay Kit.

KEY FINDINGS: The results showed opposing effects of MA on Nrf2 expression in HUVECs and THP-1 macrophages. MA suppressed TNF-α-induced Nrf2 expression in HUVECs, but enhanced its expression in THP-1 macrophages. Combined effects of MA and ML385 suppressed MCP-1, VCAM-1, and SR-A expressions. Intriguingly, at the protein level, ML385 selectively inhibited SR-A but enhanced CD36 expression. Meanwhile, ML385 further enhanced MA-mediated inhibition of NF-κB activity in HUVECs. This effect, however, was not observed in THP-1 macrophages.

METHODS: Maximal non-toxic dose (MNTD) of methanol extract of P. ginseng root culture on BV2 microglia cells was first determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, followed by treatment and LPS stimulation of cells, and the measurement of NO using Griess assay and TNF-α, IL-6, and IL-10 using ELISA assay.

RESULTS: The MNTD of P. ginseng root extract was determined to be (587 ± 57) µg/mL. Following that, NO and IL-6 levels were found to be insignificantly reduced by 6.88% and 0.14% respectively in stimulated cells upon treatment with MNTD. Treatment with MNTD yielded similar insignificant result, with only a reduction of 3.58% and 0.08% in NO and IL-6 levels respectively. However, TNF-α and IL-10 levels were significantly downregulated by 15.64% and 34.96% respectively upon treatment with P. ginseng root extract at MNTD.

Methods: In this study, type 2 diabetes model mice were induced by streptozotocin and high-fat diet (HFD) and used to evaluate the antihyperglycemic and anti-inflammatory effects of FFP. Mice were fed with HFD and challenged with 30 mg/kg body weight (BW) of streptozotocin for 1 month followed by 6 weeks of supplementation with 0.1 and 1.0 g/kg BW of FFP. Metformin was used as positive control treatment.

Results: Xeniji™-supplemented hyperglycemic mice were recorded with lower glucose level after 6 weeks of duration. This effect was contributed by the improvement of insulin sensitivity in the hyperglycemic mice indicated by the oral glucose tolerance test, insulin tolerance test, and end point insulin level. In addition, gene expression study has shown that the antihyperglycemic effect of FFP is related to the improvement of lipid and glucose metabolism in the mice. Furthermore, both 0.1 and 1 g/kg BW of FFP was able to reduce hyperglycemia-related inflammation indicated by the reduction of proinflammatory cytokines, NF-kB and iNOS gene expression and nitric oxide level.

METHODS: The release of prostaglandin E2 (PGE2) and pro-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β in a culture supernatant was determined by ELISA. Determination of cyclooxygenase-2 (COX-2) protein and the activation of MAPKs molecules (JNK, ERK and p38 MAPK), NF-κB and Akt in LPS-induced U937 human macrophages were investigated by immunoblot technique. The relative gene expression levels of COX-2 and pro-inflammatory cytokines were measured by using qRT-PCR. The major metabolites of P. amarus were qualitatively and quantitatively analyzed in the extract by using validated reversed-phase high performance liquid chromatography (HPLC) methods.

RESULTS: P. amarus extract significantly inhibited the production of pro-inflammatory mediators (TNF-α, IL-1β, PGE2) and COX-2 protein expression in LPS-induced U937 human macrophages. P. amarus-pretreatment also significantly downregulated the increased mRNA transcription of pro-inflammatory markers (TNF-α, IL-1β, and COX-2) in respective LPS-induced U937 macrophages. It downregulated the phosphorylation of NF-κB (p65), IκBα, and IKKα/β and restored the degradation of IκBα, and attenuated the expression of Akt, JNK, ERK, and p38 MAPKs phosphorylation in a dose-dependent manner. P. amarus extract also downregulated the expression of upstream signaling molecules, TLR4 and MyD88, which play major role in activation of NF-κB, MAPK and PI3K-Akt signaling pathways. The quantitative amounts of lignans, phyllanthin, hypophyllahtin and niranthin, and polyphenols, gallic acid, geraniin, corilagin, and ellagic acid in the extract were determined by HPLC analysis.

METHODS: Interleukin (IL)-6 cytokine production in histamine-induced HaCaT cells were measured using enzyme-linked immunosorbent assay (ELISA) and cytotoxicity effects were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Real-time polymerase chain reaction (RT-qPCR) was carried out to determine the inhibitory effects of MS65 on nuclear factor-kappa B (NF-κB) and mitogen activated protein kinase (MAPK) pathways.

RESULTS: Histamine enhanced IL-6 production in HaCaT cells, with the highest production of IL-6 at 97.41 ± 2.33 pg/mL after 24 h of exposure. MS65 demonstrated a promising anti-inflammatory activity by inhibiting IL-6 production with half maximal inhibitory concentration (IC50) value of 4.91 ± 2.50 μM and median lethal concentration (LC50) value of 28.82 ± 7.56 μM. In gene expression level, we found that MS65 inhibits NF-κB and MAPK pathways through suppression of IKK/IκB/NFκB and c-Raf/MEK/ERK inflammatory cascades.

METHOD: Rosmarinic acid was isolated by bioactivity-guided isolation from butanolic fraction of Punica granatum and acute toxicity of rosmarinic acid was carried out. The experiment was conducted at doses of 25 and 50 mg/kg, in Freund's complete adjuvant (FCA)-induced arthritic rats. Various parameters, that is arthritic score, paw volume, thickness of paw, hematological, antioxidant and inflammatory parameters such as glutathione (GSH), superoxide dismutase (SOD), malonaldehyde (MDA) and tumor necrosis factor-α (TNF-α) were also estimated.